For centuries this was the symbolic heart of Tsarist rule. The square is centred on the impressive Cathedral of the Assumption, built as the great seat of the Russian Orthodox Church and the oldest and largest of the Kremlin's churches. Tsars were invested and emperors were crowned in this cathedral, whose frescoes and icons are of particular interest.

The Cathedral of the Annunciation, with its golden domes, was the private chapel of the Russian princes and tsars. The deans of the Cathedral were usually the confessors to tsars. The porch was built by Ivan the Terrible in 1572 after he contravened church doctrine by marrying for a fourth time. He was asked to refrain from entering the cathedral to attend services because of this marriage and so had the porch built. From here he carried out his religious devotions, behind a specially constructed grille.

The Cathedral of the Archangel Michael was built in 1505 as the burial place for the early tsars and their predecessors, the princes of Moscow. Built by the Venetian architect Alevisio, the Italian Renaissance influence is apparent in the scallop-shell decoration of its gables. Around the walls and pillars are the tombs of many of Russia's rulers up to the eighteenth century.

Intended to defend the Saviour Gate, the Tsar Cannon is the largest of its kind in the world. With a barrel in excess of five-metres long, it weighs 40 tons but has never been fired. Likewise, the Tsar Bell has never rung and it too is the largest in the world. A smaller bell was built in the middle of the seventeenth century, but was destroyed in the Moscow fire of 1701. The Empress Anna ordered the fragments to be recast into a much larger bell, but it cracked in 1737, after falling into its casting pit. It was placed in its present position a hundred years later.

Dominating Cathedral Square is the gleaming, gilt dome of the Ivan the Great Bell Tower. Built in bright, white stone, it soars to a height of over 80 metres, providing a focal point for the entire Kremlin.